So Riot's plan to get Flash used less (which won't happen) is to raise the CD on it...again. At least ignite's purpose is to counter heal, flash's only counter is flash which is why so many players take flash. You could always just make every other spell better so that people might actually use Surge once in a while. unless the numbers on Barrier get toned down a lot or the CD on it in SR goes up considerably I don't see it being very balanced either, that is if people even decide to use it, which I'm sure it'll replace Heal for the most part.
I do like the prospect of getting Item repathing and items getting additional options, everythin except the summoner spells section looks very promising, but seriously Riot, you can't nerf flash or raise it's CD high enough to make it less appealing unless we're talkign like Revive CD levels. Everyone is still going to use it and Phreak is going to recommend that EVERY champion takes it along with ignite unless your jungling at which point you should Flash/Smite. It's a nice idea, but the utility of it is way too overbearing.
If there was no Flash in LoL then game flow would change considerably because people would I don't know, actually have to think ahead more often, and I think that would be looked down upon at first but once everyone got over it I think overall gameplay would improve. In the end it's an addiction, and I think it would be much better in the longrun if it was removed and replaced by Barrier instead of simply adding Barrier.